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Leme VFC, Lopez K, Costa T, Conerty B, B Leonelli L, Zhang Y, Davidson PC. Hydrothermal liquefaction aqueous phase mycoremediation to increase inorganic nitrogen availability. Heliyon 2024; 10:e31992. [PMID: 38882322 PMCID: PMC11176836 DOI: 10.1016/j.heliyon.2024.e31992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 05/23/2024] [Accepted: 05/27/2024] [Indexed: 06/18/2024] Open
Abstract
Hydrothermal liquefaction aqueous phase (HTL-AP) is a waste product from a thermochemical process where wet biomass is converted into biocrude oil. This nutrient-rich wastewater may be repurposed to benefit society by assisting crop growth after adequate treatment to increase inorganic nitrogen, especially NO3 -. This study aims to increase HTL-AP inorganic nitrogen, specifically NH3/NH4 + and NO3 -, through fungal remediation for further use in hydroponic systems. Trametes versicolor, a white-rot fungus known for degrading a range of organic pollutants, was used to treat a diluted (5 %) HTL-AP for 9 days. No fungal growth was observed, but T. versicolor activity was suspected by laccase activity throughout cultivation time. NO3 --N and NH3/NH4 +-N increased by 17 and 8 times after three days of fungal treatment, which was chosen as the appropriate time for HTL-AP fungal treatment as it resulted in the highest concentration of NO3 --N. The addition of nitrifying bacteria to the fungal treatment resulted in a twofold increase in NO3 --N concentration compared to the fungal treatment alone, indicating an enhancement in treatment efficacy. COD decreased by 51.33 % after 24 h, which may be related to the fungus' capacity to reduce the concentration of organics in the wastewater; nonetheless, COD increased in the following days, which may be related to the release of fungal byproducts. T. versicolor shows promise as a potential candidate for increasing inorganic nitrogen in HTL-AP. However, future studies should primarily address HTL-AP toxicity, reducing NH3/NH4 +-N while increasing NO3 --N, and hydroponics crop production after fungal treatment.
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Affiliation(s)
- Vitoria F C Leme
- Agricultural & Biological Engineering, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | - Karla Lopez
- Agricultural & Biological Engineering, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | - Tiago Costa
- Agricultural & Biological Engineering, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | - Beth Conerty
- Agricultural & Biological Engineering, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | - Laurie B Leonelli
- Agricultural & Biological Engineering, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | - Yuanhui Zhang
- Agricultural & Biological Engineering, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | - Paul C Davidson
- Agricultural & Biological Engineering, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
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Ramírez-Romero A, da Costa Magalhães B, Matricon L, Sassi JF, Steyer JP, Delrue F. Aqueous phase recycling: impact on microalgal lipid accumulation and biomass quality. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024:10.1007/s11356-024-32701-7. [PMID: 38438644 DOI: 10.1007/s11356-024-32701-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 02/25/2024] [Indexed: 03/06/2024]
Abstract
The potential success of microalgal biofuels greatly depends on the sustainability of the chosen pathway to produce them. Hydrothermal liquefaction (HTL) is a promising route to convert wet algal biomass into biocrude. Recycling the resulting HTL aqueous phase (AP) aims not only to recover nutrients from this effluent but also to use it as a substrate to close the photosynthetic loop and produce algal biomass again and process this biomass again into new biocrude. With that purpose, the response to AP recycling of five Chlorellaceae strains was monitored over five cultivation cycles. After four successive cycles of dynamic growth under nutrient-replete conditions, the microalgae were cultivated for a prolonged fifth cycle of 18 days in order to assess the impact of the AP on lipid and biomass accumulation under nutrient-limited conditions. Using AP as a substrate reduced the demand for external sources of N, S, and P while producing a significant amount of biomass (2.95-4.27 g/L) among the strains, with a lipid content ranging from 16 to 36%. However, the presence of the AP resulted in biomass with suboptimal properties, as it slowed down the accumulation of lipids and thus reduced the overall energy content of the biomass in all strains. Although Chlorella vulgaris NIES 227 did not have the best growth on AP, it did maintain the best lipid productivity of all the tested strains. Understanding the impact of AP on microalgal cultivation is essential for further optimizing biofuel production via the HTL process.
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Affiliation(s)
- Adriana Ramírez-Romero
- MicroAlgae Processes Platform-CEA, CEA Tech Région Sud, 13108, Saint-Paul-Lez-Durance, France.
- Laboratoire de Biotechnologie de L'Environnement (LBE), INRAE, Univ Montpellier, 102 Avenue Des Etangs, 11100, Narbonne, France.
| | - Bruno da Costa Magalhães
- Institut de Recherches Sur La Catalyse Et L'Environnement de Lyon (IRCELYON), UMR 5256, CNRS, Université Claude Bernard Lyon1, 2 Av. Albert Einstein, 69626, Villeurbanne, France
| | - Lucie Matricon
- CEA LITEN, Université Grenoble Alpes, 38000, Grenoble, France
| | - Jean-François Sassi
- MicroAlgae Processes Platform-CEA, CEA Tech Région Sud, 13108, Saint-Paul-Lez-Durance, France
| | - Jean-Philippe Steyer
- Laboratoire de Biotechnologie de L'Environnement (LBE), INRAE, Univ Montpellier, 102 Avenue Des Etangs, 11100, Narbonne, France
| | - Florian Delrue
- MicroAlgae Processes Platform-CEA, CEA Tech Région Sud, 13108, Saint-Paul-Lez-Durance, France
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Zhou Y, Remón J, Pang X, Jiang Z, Liu H, Ding W. Hydrothermal conversion of biomass to fuels, chemicals and materials: A review holistically connecting product properties and marketable applications. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 886:163920. [PMID: 37156381 DOI: 10.1016/j.scitotenv.2023.163920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 04/12/2023] [Accepted: 04/29/2023] [Indexed: 05/10/2023]
Abstract
Biomass is a renewable and carbon-neutral resource with good features for producing biofuels, biochemicals, and biomaterials. Among the different technologies developed to date to convert biomass into such commodities, hydrothermal conversion (HC) is a very appealing and sustainable option, affording marketable gaseous (primarily containing H2, CO, CH4, and CO2), liquid (biofuels, aqueous phase carbohydrates, and inorganics), and solid products (energy-dense biofuels (up to 30 MJ/kg) with excellent functionality and strength). Given these prospects, this publication first-time puts together essential information on the HC of lignocellulosic and algal biomasses covering all the steps involved. Particularly, this work reports and comments on the most important properties (e.g., physiochemical and fuel properties) of all these products from a holistic and practical perspective. It also gathers vital information addressing selecting and using different downstream/upgrading processes to convert HC reaction products into marketable biofuels (HHV up to 46 MJ/kg), biochemicals (yield >90 %), and biomaterials (great functionality and surface area up to 3600 m2/g). As a result of this practical vision, this work not only comments on and summarizes the most important properties of these products but also analyzes and discusses present and future applications, establishing an invaluable link between product properties and market needs to push HC technologies transition from the laboratory to the industry. Such a practical and pioneering approach paves the way for the future development, commercialization and industrialization of HC technologies to develop holistic and zero-waste biorefinery processes.
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Affiliation(s)
- Yingdong Zhou
- College of Materials and Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu 610059, PR China; China Leather and Footwear Research Institute Co. Ltd., Beijing 100015, PR China
| | - Javier Remón
- Thermochemical Processes Group, Aragón Institute for Engineering Research (I3A), University of Zaragoza, C/Mariano Esquillor s/n, 50.018, Zaragoza, Spain.
| | - Xiaoyan Pang
- China Leather and Footwear Research Institute Co. Ltd., Beijing 100015, PR China
| | - Zhicheng Jiang
- College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, PR China
| | - Haiteng Liu
- China Leather and Footwear Research Institute Co. Ltd., Beijing 100015, PR China
| | - Wei Ding
- China Leather and Footwear Research Institute Co. Ltd., Beijing 100015, PR China.
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Ramírez-Romero A, Martin M, Boyer A, Bolzoni R, Matricon L, Sassi JF, Steyer JP, Delrue F. Microalgae adaptation as a strategy to recycle the aqueous phase from hydrothermal liquefaction. BIORESOURCE TECHNOLOGY 2023; 371:128631. [PMID: 36646358 DOI: 10.1016/j.biortech.2023.128631] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/11/2023] [Accepted: 01/12/2023] [Indexed: 06/17/2023]
Abstract
Hydrothermal liquefaction (HTL) produces bio-crude oil from wet algae along with an aqueous phase (AP). This effluent contains minerals that can be reused for cultivating new microalgae but whose utility remains limited due to the presence of inhibitors. Reduced photosynthetic performance, growth, and null lipid accumulation were observed in wild-type Chlorella vulgaris NIES 227 cultivated in AP (1/200). Adaptive laboratory evolution was studied by batch transfers and turbidostat mode. Both methods effectively counterbalanced AP toxicity and restored the fitness of the microalgae. After adaptation, a higher AP addition was achieved, from 1/600 to 1/200, without inhibition. As compared with the wild typein control medium (0.261 g/L/d), both adapted-strains maintained competitive productivity (0.310 and 0.258 g/L/d) of lipid-rich biomass (37 %-56 %). The improved tolerance of the adapted strains persisted after the removal of AP and under axenic conditions. Adaptive laboratory evolution is suggested for AP reutilization in the algae production process.
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Affiliation(s)
- Adriana Ramírez-Romero
- MicroAlgae Processes Platform-CEA, CEA Tech Région Sud, 13108 Saint-Paul-lez-Durance, France; Laboratoire de Biotechnologie de l'Environnement (LBE), INRAE, Univ. De Montpellier, 102 Avenue des Etangs, 11100 Narbonne, France.
| | - Marion Martin
- MicroAlgae Processes Platform-CEA, CEA Tech Région Sud, 13108 Saint-Paul-lez-Durance, France
| | - Alana Boyer
- MicroAlgae Processes Platform-CEA, CEA Tech Région Sud, 13108 Saint-Paul-lez-Durance, France
| | - Romain Bolzoni
- Aix-Marseille University, CNRS, CEA, UMR7265, Institute of Biosciences and Biotechnologies of Aix-Marseille, CEA Cadarache, F-13108, Saint-Paul-lez-Durance, France
| | - Lucie Matricon
- CEA LITEN, Université Grenoble Alpes, 38000 Grenoble, France
| | - Jean-François Sassi
- MicroAlgae Processes Platform-CEA, CEA Tech Région Sud, 13108 Saint-Paul-lez-Durance, France
| | - Jean-Philippe Steyer
- Laboratoire de Biotechnologie de l'Environnement (LBE), INRAE, Univ. De Montpellier, 102 Avenue des Etangs, 11100 Narbonne, France
| | - Florian Delrue
- MicroAlgae Processes Platform-CEA, CEA Tech Région Sud, 13108 Saint-Paul-lez-Durance, France
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Behera B, Mari Selvam S, Balasubramanian P. Hydrothermal processing of microalgal biomass: Circular bio-economy perspectives for addressing food-water-energy nexus. BIORESOURCE TECHNOLOGY 2022; 359:127443. [PMID: 35697260 DOI: 10.1016/j.biortech.2022.127443] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 06/05/2022] [Accepted: 06/07/2022] [Indexed: 06/15/2023]
Abstract
Hydrothermal processing of microalgae is regarded as a promising technology to generate multitude of energy based and value-added products. The niche of hydrothermal technologies is still under infancy in terms of the technical discrepancies related to research and development. Thus, the present review critically surveyed the recent advancements linked to the influencing factors governing the algal hydrothermal processing in terms of the product yield and quality. The sustainability of hydrothermal technologies as a standalone method and in broader aspects of circular bio-based economy for energy and value-added platform chemicals are comprehensively discussed. Process optimization and strategic integration of technologies has been suggested to improve efficiency, with reduced energy usage and environmental impacts for addressing the energy-food-water supply chains. Within the wider economic transition and sustainability debate, the knowledge gaps identified and the research hotspots fostering future perspective solutions proposed herewith would facilitate its real-time implementation.
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Affiliation(s)
- Bunushree Behera
- Agricultural & Environmental Biotechnology Group, Department of Biotechnology and Medical Engineering, National Institute of Technology Rourkela, India.
| | - S Mari Selvam
- Agricultural & Environmental Biotechnology Group, Department of Biotechnology and Medical Engineering, National Institute of Technology Rourkela, India
| | - Paramasivan Balasubramanian
- Agricultural & Environmental Biotechnology Group, Department of Biotechnology and Medical Engineering, National Institute of Technology Rourkela, India
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Hu ZY, Jiang SF, Shi XY, Jiang H. Simultaneous recovery of nutrients and improving the biodegradability of waste algae hydrothermal liquid. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 307:119556. [PMID: 35675879 DOI: 10.1016/j.envpol.2022.119556] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/21/2022] [Accepted: 05/28/2022] [Indexed: 06/15/2023]
Abstract
The ever-increasing algae biomass due to eutrophication brings an enormous destruction and potential threat to the ecosystem. Hydrothermal carbonization (HTC) is a potential means converting algae to value added products such as sustainable bioenergy and biomaterials. However, the waste aqueous phase (AP) produced during the HTC of algae biomass needs to be treated carefully in case of the second pollution to environment. In this study, a model microbe (E. coli) was adopted for the microbial pretreatment of AP, by which the bioavailability of AP could be improved, and the nutrients could be reclaimed though struvite precipitation. Three-dimensional fluorescence spectra and GC-MS results illustrated that E. coli pretreatment could convert a large number of organic nitrogenous compounds to ammonia nitrogen by degrading aromatic protein substances and deaminating nitrogenous heterocyclic compounds. Afterwards, a serious of characterizations confirmed that 81.13% of ammonia nitrogen could be recovered as struvite though precipitation. Life cycle assessment indicates the cost of the two-step treatment process was much lower than that of conventional wastewater treatment processes, and is beneficial to environment. This work provides an environment-friendly strategy for the comprehensive utilization of algae, which may contribute to alleviating the algal disasters and bring certain economic benefits though algal treatment.
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Affiliation(s)
- Zi-Ying Hu
- Department of Applied Chemistry, University of Science and Technology of China, Hefei, 230026, China
| | - Shun-Feng Jiang
- Department of Applied Chemistry, University of Science and Technology of China, Hefei, 230026, China
| | - Xian-Yang Shi
- Anhui Province Key Laboratory of Wetland Ecosystem Protection and Restoration, School of Resource and Environmental Engineering, Anhui University, Hefei, 230601, China
| | - Hong Jiang
- Department of Applied Chemistry, University of Science and Technology of China, Hefei, 230026, China.
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7
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Beneficial use of the aqueous phase generated during hydrothermal carbonization of algae as nutrient source for algae cultivation. ALGAL RES 2021. [DOI: 10.1016/j.algal.2021.102485] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Swetha A, ShriVigneshwar S, Gopinath KP, Sivaramakrishnan R, Shanmuganathan R, Arun J. Review on hydrothermal liquefaction aqueous phase as a valuable resource for biofuels, bio-hydrogen and valuable bio-chemicals recovery. CHEMOSPHERE 2021; 283:131248. [PMID: 34182640 DOI: 10.1016/j.chemosphere.2021.131248] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 05/10/2021] [Accepted: 06/14/2021] [Indexed: 06/13/2023]
Abstract
Hydrothermal liquefaction (HTL) of biomass results in the formation of bio-oil, aqueous phase (HTL-AP), bio-char, and gaseous products. Safer disposal of HTL-AP is difficult on an industrial scale since it comprises low molecular acid compounds. This review provides a comprehensive note on the recent articles published on the effective usage of HTL-AP for the recovery of valuable compounds. Thermo-chemical and biological processes are the preferred techniques for the recovery of biofuel, platform chemicals from HTL-AP. From this review, it was evident that the composition of HTL-AP and product recovery are the integrated pathways, which depend on each other. Substitute as reaction medium in HTL process, growth medium for algae and microbes are the most common mode of reuse and recycle of HTL-AP. Future research is needed to depict the mechanism of HTL process when HTL-AP is used as a reaction medium on an industrial scale. Need to find a solution for the hindrance in commercializing HTL process and recovery of value-added compounds from HTL-AP from lab scale to industry level. Integrated pathways on reuse and HTL-AP recycle helps in reduced environmental concerns and sustainable production of bio-products.
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Affiliation(s)
- Authilingam Swetha
- Department of Chemical Engineering, Sri Sivasubramaniya Nadar College of Engineering, Kalavakkam, 603110, Tamil Nadu, India
| | - Sivakumar ShriVigneshwar
- Department of Chemical Engineering, Sri Sivasubramaniya Nadar College of Engineering, Kalavakkam, 603110, Tamil Nadu, India
| | | | - Ramachandran Sivaramakrishnan
- Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Rajasree Shanmuganathan
- Innovative Green Product Synthesis and Renewable Environment Development Research Group, Faculty of Environment and Labour Safety, Ton Duc Thang University, Ho Chi Minh City, Viet Nam
| | - Jayaseelan Arun
- Center for Waste Management - 'International Research Centre', Sathyabama Institute of Science and Technology, Jeppiaar Nagar (OMR), Chennai, 603119, Tamil Nadu, India.
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Mahima J, Sundaresh RK, Gopinath KP, Rajan PSS, Arun J, Kim SH, Pugazhendhi A. Effect of algae (Scenedesmus obliquus) biomass pre-treatment on bio-oil production in hydrothermal liquefaction (HTL): Biochar and aqueous phase utilization studies. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 778:146262. [PMID: 33714809 DOI: 10.1016/j.scitotenv.2021.146262] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Revised: 02/19/2021] [Accepted: 02/28/2021] [Indexed: 06/12/2023]
Abstract
Environmental concerns due to fossil fuel usage has turned the research interest towards biomass and bioenergy field. Renewable biomass such as microalgae provides numerous advantages as they can grow in wastewater; sequester carbon dioxide, economical and eco-friendly. In this study, effect of pretreatment of microalgae (Scenedesmus obliquus) biomass using post-hydrothermal liquefaction wastewater (PHWW) for bio-oil production through hydrothermal liquefaction at a temperature of 300 °C was studied. Results showed liquefaction of pre-treated biomass yielded 48.53% bio-oil whereas 28.35% was resulted from biomass without pretreatment. The analysis of higher heating value of bio-oil showed that pretreated biomass oil has 36.19 MJ.Kg-1 against non-pretreated biomass oil, which has 28.88 MJ.Kg-1. Bio-oil (pretreated biomass) analysis revealed that 60% of compounds are in diesel and gasoline range with 58.09% of energy recovery. Bio-oil was rich in hydrocarbons of C7-C21 range with less oxygenated compounds. Carbon balance showed that an increase of 13% of carbon was sequestered in solid residue obtained from pretreated biomass and about 146% of increase also obtained in bio-oil.
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Affiliation(s)
- Jain Mahima
- Department of Chemical Engineering, Sri Sivasubramaniya Nadar College of Engineering, Kalavakkam 603110, Tamil Nadu, India
| | - Ramesh Kumar Sundaresh
- Department of Chemical Engineering, Sri Sivasubramaniya Nadar College of Engineering, Kalavakkam 603110, Tamil Nadu, India
| | | | - Panneer Selvam Sundar Rajan
- Department of Chemical Engineering, Sri Sivasubramaniya Nadar College of Engineering, Kalavakkam 603110, Tamil Nadu, India
| | - Jayaseelan Arun
- Centre for Waste Management, International Research Centre, Sathyabama Institute of Science and Technology, Jeppiaar Nagar (OMR), Chennai 600119, Tamil Nadu, India
| | - Sang-Hyoun Kim
- School of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Arivalagan Pugazhendhi
- School of Renewable Energy, Maejo University, Chiang Mai 50290, Thailand; College of Medical and Health Science, Asia University, Taichung, Taiwan.
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Techno-economic analysis and global warming potential of a novel offshore macroalgae biorefinery. ALGAL RES 2020. [DOI: 10.1016/j.algal.2020.102032] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Choudhary P, Assemany PP, Naaz F, Bhattacharya A, Castro JDS, Couto EDADC, Calijuri ML, Pant KK, Malik A. A review of biochemical and thermochemical energy conversion routes of wastewater grown algal biomass. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 726:137961. [PMID: 32334349 DOI: 10.1016/j.scitotenv.2020.137961] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 03/13/2020] [Accepted: 03/13/2020] [Indexed: 06/11/2023]
Abstract
Microalgae are recognized as a potential source of biomass for obtaining bioenergy. However, the lack of studies towards economic viability and environmental sustainability of the entire production chain limits its large-scale application. The use of wastewaters economizes natural resources used for algal biomass cultivation. However, desirable biomass characteristics for a good fuel may be impaired when wastewaters are used, namely low lipid content and high ash and protein contents. Thus, the choice of wastewaters with more favorable characteristics may be one way of obtaining a more balanced macromolecular composition of the algal biomass and therefore, a more suitable feedstock for the desired energetic route. The exploration of biorefinery concept and the use of wastewaters as culture medium are considered as the main strategic tools in the search of this viability. Considering the economics of overall process, direct utilization of wet biomass using hydrothermal liquefaction or hydrothermal carbonization and anaerobic digestion is recommended. Among the explored routes, anaerobic digestion is the most studied process. However, some main challenges remain as little explored, such as a low energy pretreatment and suitable and large-scale reactors for algal biomass digestion. On the other hand, thermochemical conversion routes offer better valorization of the algal biomass but have higher costs. A biorefinery combining anaerobic digestion, hydrothermal carbonization and hydrothermal liquefaction processes would provide the maximum possible output from the biomass depending on its characteristics. Therefore, the choice must be made in an integrated way, aiming at optimizing the quality of the final product to be obtained. Life cycle assessment studies are critical for scaling up of any algal biomass valorization technique for sustainability. Although there are limitations, suitable integrations of these processes would enable to make an economically feasible process which require further study.
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Affiliation(s)
- Poonam Choudhary
- Applied Microbiology Laboratory, Centre for Rural Development and Technology, IIT Delhi, 110016, India
| | - Paula Peixoto Assemany
- Universidade Federal de Viçosa/Civil Engineering Department, Avenida PH Rolfs s/n, 36570-900 Viçosa, MG, Brazil.
| | - Farah Naaz
- Applied Microbiology Laboratory, Centre for Rural Development and Technology, IIT Delhi, 110016, India
| | - Arghya Bhattacharya
- Applied Microbiology Laboratory, Centre for Rural Development and Technology, IIT Delhi, 110016, India
| | - Jackeline de Siqueira Castro
- Universidade Federal de Viçosa/Civil Engineering Department, Avenida PH Rolfs s/n, 36570-900 Viçosa, MG, Brazil.
| | - Eduardo de Aguiar do Couto Couto
- Universidade Federal de Itajubá/Itabira campus, Instituto de Ciências Puras e Aplicadas, Rua Irmã Ivone Drummond, 200, 35903-087 Itabira, MG, Brazil.
| | - Maria Lúcia Calijuri
- Universidade Federal de Viçosa/Civil Engineering Department, Avenida PH Rolfs s/n, 36570-900 Viçosa, MG, Brazil.
| | - Kamal Kishore Pant
- Catalytic Reaction Engineering Laboratory, Department of Chemical Engineering, IIT Delhi, 110016, India.
| | - Anushree Malik
- Applied Microbiology Laboratory, Centre for Rural Development and Technology, IIT Delhi, 110016, India.
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